Called when a FormItem's value is about to change as the result of user interaction. This
method fires after the user performed an action that would change the value of this field,
but before the element itself is changed.
Returning false cancels the change. Note that if what you want to do is
transform the user's input, for example, automatically change separator
characters to a standard separator character, you should implement
FormItem.setInputTransformer(com.smartgwt.client.widgets.form.FormItemInputTransformer)
rather than using a combination of
change() and setValue() to accomplish the same thing. Returning false from
change
is intended for rejecting input entirely, such as typing invalid
characters.
Note that if you ask the form for the current value in this handler, you will get the old
value because the change has not yet been commited. The new value is available as a
parameter to this method.
- Parameters:
handler
- the change handler
- Returns:
HandlerRegistration
used to remove this handler